Niter-oven.



N0. 694,024. Patented Fb. 25, |902` Y A. P. BFHEN.` A

NITEB OVEN.

(Appliclyion led June 8. 1901.) (No Modal.)

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if" y UNITED STATES PATENT EEICE.

ANDREW P. OBRIEN, OF RICHMOND, VIRGINIA.

NITER-OVEN.

SPECIFICATION forming part of Letters Patent No. 694,024; dated February 25, 1902.

Application filed June 6, 1901. ASerial No. 63.445. (No model.)

T0 all whom t may concern:

Be it known that I, ANDREW P. OBRIEN, a citizen of the United States, residing at Richmond, in the county of Henrico and State of Virginia, have invented certain new and useful Improvements in Niter-Ovens; and I do hereby declare the following to be a full, clear, and exact description o f the invention, such as Will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in niter-ovens, and particularly to that style of oven which is capable of collecting dust which may pass through the oven with the heating agency on its way to other parts .of the apparatus with which the oven may be connected.

It consists in an oven formed in a cylindrical or cylindrical and conical shape, a series of niter pots or receptacles arranged in the said oven, and means for introducing the heating agent into the said oven, so that any dust or particles carried thereby will be given a whirling movement and so that the said dust or foreign particles may be collected in the bottom of the oven and will not pass out of the same with the blast or draft which carries the gases from the oven.

It also consists of a niter-oven formed of a .suitable shape and having a series of niterpots arranged therein, the tops of which project through the top ofthe oven, while the lower ends extend through the lower walls of the oven, means for closing the lower ends ofthe niter-pots, and a niter-cake pan arranged about the oven below theoutlets of the said niter-pots for receiving the contents thereof from time to time. v y

l It also consists in certain other novel con-A structions, combinations, and arrangements of parts, as will be hereinafter fully described and specifically claimed. y

In the accompanying drawings,vFigure l represents a vertical central cross -section through a niter-oven constructed in accordance with the present invention.' Fig. 2 is a top plan viewof the same. Fig. 3 is an enlarged detailI ,sectional View through the upper end of one of the niter-pots.

In connection 'with certain metallurgical operations-as, for instance, the production of sulfuric acid, in which the initial step of thc process consists in roast-ing certain ores,

as sulfur compounds or pyrites-it is common to use means in connection ltherewith for producing nitric acid, the nitrate of soda or the nitrate of potassium being placed in what are known as niterpots, together f with sulfuric acid, and heated by` means of sulfur dioxid (SO2) as it passes from the roasting-furnace, the same being applied to the niter-pots by means of an oven, the said sulfur dioxid passing from the said oven to a Glovers tower or denitrificator and other chambers of the apparatus. The nitric acid is thus produced in the niter-pots in a gaseous state and passes out of the oven, together with the sulfur dioxid, on its way to the Glovers tower. The great difficulty with this kind of apparatus heretofore has been that in burning pyrites, especially of ne ore, great quantities of line Hue-dust, so called, is carried along by the draft, and this dust isfound t0 bevery injurious to the properworkingof the Glovers tower, somuch so, in fact, that some manufacturers have ceased using fine ore and use the more expensive lump ore or brimstone. By the present invention this injurious dust can be automatically collected and removed from the draft coming from thefurnaces and passing through the niter-hoven, so that the same cannot enter the Glovers tower. The flow of heated sulfur dioXid can, however, be used to heat` the niter-pots and produce the nitric acid. Y

This invention also provides superior means for taking care of the sodium sulfate or niter cake `which is produced in the niter-pots,l

tion takingplace therein.

In employing my invention in practical form I construct the niter-ovenl of a suitable casing of metal, lining the same with brick or other material, as at 2. The ovenisv j preferably of a conical shape for about two-A Y thirds of its length at its lower end, the remaining one-third being preferably cylindrical. The oven is closed at the top bya suitable coverl or top plate, as 3. Arranged with- :in the oven are a series of-niter-pots 44,

vwhich preferably project through the wall of the oven-say about vone-half way down' the same. The lower ends of the niter-pots are formed with discharge-openings, which are adapted to be closed by gates or valves 5 5,

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which are pivoted to the oven and are heldin their closed positions by ad justing-screws 6 G. The construction of the upper ends of the niter-pots, together with the covers for closing the same, forms an important feature of the invention. In the upper end of each niterpot a Iianged sleeve, as 7, is located, which extends some little distance into the top of the pot and is formed with an opening, as 8,

which may be brought to correspond with the corresponding opening 9,for1ned in each niterpot. Byturningthe sleeve this opening may be closed or opened, according as the aperture 8 is brought into or out of coincidence with the aperture 9. An annular rib or knifeedge, as 10, engages the under side of fiange 11 of said sleeve, forming therewith a gastight joint. Resting upon the top of thesleeve or collar 7 is a cover 12, which engages an annular flange or knife-edge 13 upon the upper edge of the sleeve 7, so as to form therewith a gas-tight joint. The cover 12 is formed with a handle 14, by which the cover may be turned or lifted from position. Upon the under side of the cover '12 are arranged dowelpins 15 15, which engage correspondinglyformed recesses 16 16 in the horizontalange of the sleeve 7. Through the agency of these dowel-pins the sleeve 7 may be rotated in the top of the niter-pot by turning the cover 12. When the niter-pot has been charged and nitric-acid gas is being evolved therein, the sleeve 7 is turned so that the aperture 8 coincides with the aperture 9, and the gas is permitted to escape into the oven.

When it is desired to open the niter-pot and insert a new charge therein, the cover 12 is first turned so as to move the sleeve 7 and remove the `aperture 8 from the aperture 9 for closing the outlet for the gas into the said oven. The gas and sulfur dioXid passing through the oven will thus be prevented from escaping through the open top of the niterpot and a new charge may be inserted at the top of the pot. The residuum in the niterpot maybe discharged therefrom at any time by opening the gates or valves 5.

The covers 12 12 are preferably formed with inlet-openings, as 17, which are guarded by means of lutes 1S. The acid which is to act upon the nitrate of sodium and nitrate of potassium in the niter-pots may be inserted through said luted openings in the cover by means of a hose or tube from any suitable reservoir from time to time as required. The gas in the niter-pots, however, cannot escape through said openings on account of the guardinglutes. Entering the top of the niter-oven 1 is an outlet-tube 19, which projects some little distance into the said oven, preferably more than one-half way down the same. The outlet passes out through the center of the top 3 and leads to a Glovers tower, Gay-Lussac tower, or other chambers of the apparatus in connection with which the niter-oven is used for conveying the nitricacid gas and sulfur dioxid from the said oven.

The sulfur dioXid for heating the 'niter-pot in the oven is introduced into the oven from the roasting-furnace by means of a pipe 20, which enters the said oven tangentially at a point near the top of the oven, or at least at a considerable distance above the lower open end of the exit-pipe 19. The sulfur dioxid thus entering the oven will receive a whirling movement, passing around the inner periphery of the oven a number of times before it can reach the inverted mouth of the exit-pipe. By this means the injurious dust entering with the sulfur dioxid will be collected in the oven and will drop to the lower end thereof, so as to be entirely separated from the heating-gases passing through the oven. lower end of the oven is preferably provided with an outlet-opening, as at 21,` which is closed by a weighted gate or valve 22. VThe weight 23, secured to the said valve, normally holds the same in its closed position. This valve may be operated at any time for discharging the dust and foreign substances which collect in the bottom of the niter-oven. Arranged outside the niter-oven and below the open discharge ends of the niter-pots44 isa niter-cake pan 24, which is made of a suitf able size to receive the discharge of sodium sulfate from the niter-pots. This sodium sul fate is in liquid form when the niter-pots are being heated and readily iiows out of the lower ends of said pots when the gates 5 are opened. In order to force the sulfur dioxid through the pipe 2O into the oven 1, a fan or other blastproducing mechanism, as 25, may be located at a suitable point in the said pipe 20.

From the above description it will be observed that my apparatus is well adapted for usein depriving the sulfur dioxid coming from roasting-furnaces on its way to a Glovers tower or other apparatus of the injurious dustV which is commonly carried therebyand that the dust will be automatically collected therefrom and may be removed from the oven from time to time. When the weight of the dust in the oven exceeds the weight of the be automatically opened for discharging the dust from the oven.` The construction of the niter-pots is also advantageous, since the heat of the sulfur dioxid can be utilized to produce nitric acid, the said heat and acid gas being prevented from escaping from the oven when it is necessary to recharge the niter-pots and the nitric-acid gas being permitted to escape from the niter-pots into the oven Whenthe soda in the pots is being treated with sulfuric acid.

The apparatus will also be seen to be admirably adapted for taking care of the niter cake or sodium sulfate produced in the niterpotsby the action of the sulfuric acid on the soda. When the niter-pots are heating The y IOO IIO

`counterbalance 23, the valve or gate 22 will the niter cake is permitted to run'while in a liquid condition from the niter-pots into the niter cake pan 24 outside the oven. The niter cake can thus never interfere with the use and operation of the oven and the niterpots.

Itwill be observed that minor changes. in the construction of the apparatus may be made without departing inthe least from the spirit of my invention.

Having now described my invention, what I claimas new, and desire to secure by Letters Patent, isf 1. A niter-oven comprising acasing having an inlet and an outletvpipe, one or more niter-` pots arrangedin said oven `projecting at their lower end or ends through the walls of the said oven, and means for opening or closing communication between `the niter pot or pots with the interior of the oven, substantially as described.

2. A niter-oven comprisingacasing for receiving heated products from ore-roasting furnaces, an outlet-pipe leading from thesaid oven, a series of niterfpots arranged in the oven and projecting through the top thereof at their upper `ends while their lower ends project through the said walls of the oven,

meansfor closing both ends of the niter-pots,

and means for collecting the residue dis-y charged from said niter-pots, substantially` as described.

3. `A niter-oven comprisinga casing having a conical portion projecting to an outlet-openin g,niter-pots arranged within the oven, means for introducing a blast of heated products from a roasting or other furnace tangentially into the said oven wherebyT the niter-pots willl be heated and dust or other injurious parti-V cles may be removed by centrifugal force and gravity from the said blast, and an outlet-` pipe leading from said oven, substantially as described.

4. A niter-pot and` dust-collector compris# inga casing formedwith a .conical lowery portion, and having a discharge-opening at its lower end, an outlet-pipe for introducing heated gases from a roasting-furnace in a tan,l

gential manner into said oven near its upper end, an exit-pipe extending into the oven from the top and to a considerable distance below the inlet-opening whereby the dust brought in by the blast into the inlet-opening can be separated therefrom and collected in the bottom of theloven, and niter-pots so arranged as to extend for the greaterV portion of their,

length through the said ovens whereby they are subjected to the heat of the incoming blast,

. substantially as described,V

5. A niter-oven comprising acasing and a series lof niter-pots arranged therein, sleeves at the upper ends of the niter-pots having openings coincident with the openings in the q walls of the said niter-pots, covers for closing the said pots and resting upon the said sleeves, 7o.

tially cylindrical and partially conical, niterpots extending'from the top of the oven and i projecting at their lower ends through the walls of the conical portion of the oven, valves or gates secured to the oven-casing and adapted to close the discharge ends of the niterfpots, 8o adjusting-screws for holding the said valves in their adjusted positions, means at the upperends of the said pots for opening or close Ying communication between the interior of the pots and the interior of the oven, substantially as described. l v

7 A niter-oven comprising a casing, a seriesof niter-pots arranged therein, a sleeve movably mounted inthe upper end of each niter-pot and provided with an aperture reg- 9o istering with an aperture in the wallof each niter-pot, a cover resting upon the sleeve and provided with dowel-pins adapted to engage recesses in the ange ofthe said sleeve wherebythe sleevedmay be turned byrturning the cover,sealingribs introduced between the upper ends of the niter-pots and the flanges of the said sleeves, and between the sleeves and v the covers for preventing the escape of 'gas at 1 these points, and luted openings in the .covers IOO of theniter-pots whereby liquids may be introduced into the said pots without the escape of gas therefrom, substantially as described.

' 8. A niter-oven comprising a casing aseries of niter-pots arranged therein adapted to receiventrate of sodium or nitrate `ofpotassium and sulfuric 1 acid for producing nitric acid, the lower ends of the said pots extending through the 'wallsof the oven, a nitercake pan arranged aroundthe oven lbelowthefr ro discharge ends of the said pots for receiving the niter cake therefrom, said oven operating to apply the heat necessary to the saidpots for the carrying out of theprocess going on therein, substantially as described.

9. A niterfoven comprising a casing having a conical portion, la series of niter-pots arranged within the casing, extending through the' top thereof and having a tapering outlet projecting throughtheconical sides thereof, means for closingthe projecting ends ofthe niter-pots, andtmeans for introducing a'blast` of heated products 'from a roastingor other r Vfurnace into said oven, whereby the niterpots willbe heated,substantially as described. I 25 In testimony whereof Ighereunto affix my signature in presence of two witnesses. f

ANDREWP. QBRIEN.

Witnesses: q y 'i G. W. TAYLOR,4

J. W. GooDE. 

